Winter is coming: What to wear for outdoor work

Monday, November 02, 2015

Avoid cotton and goose down to help prevent hypothermia 

Group of workers standing outdoors in winter forest settingIn Ontario, working outside during the Canadian winter can leave workers susceptible to illnesses like hypothermia or injuries from frost bite. Hypothermia happens when the body’s core temperature drops below what is required for normal metabolism and body functions. 

“Due to the long-term effects and potential fatalities of cold injury, a few ounces of prevention are worth a pound of cure,” says Barry Austin, Health and Safety Specialist at Workplace Safety North. “Most folks from northern Ontario know the importance of dressing properly for winter. Not only do you need to stay warm and dry to prevent hypothermia during outdoor work, it’s also important to eat properly, stay active, and keep an eye on each other.

“If you know a worker who's new to the region and may be unaccustomed to colder weather, it’s important to stress these simple points, especially dressing for the weather,” adds Austin.

Dress the part: Avoid cotton and goose down

While working outdoors, winter clothing is your single most important resource to keep warm. It’s essential to dress in loose-fitting layers, which trap heat easily and allow you to adjust clothing as your activities change throughout the day. If overdressed, you’ll work up a sweat as the day progresses. 

When you’re less active, sweat starts to cool your body down, so it’s important to wear enough layers to keep warm, but not so hot as to sweat excessively. If you are sweating profusely you may be overexerting yourself; work activities and hydration should be adjusted accordingly. Be sure to add layers of clothing as your activity level decreases. Layers should be made of fabrics that retain warmth when wet such as wool, polyester fleece, and polypropylene (often found in synthetic long-johns).

Cotton is quite possibly the worst fabric to wear for warmth in winter. Once it gets wet from rain, snow or sweat, the cotton will start to extract heat out of the body. The effects are especially noticeable in cotton socks, underwear, or if a cotton T-shirt is the first layer next to skin. Goose down is an excellent insulator when dry, but because it loses almost all its insulating power when wet, it is best to avoid during winter months.

Layering Systems

Illustration showing three clothing layers for winter workwear

To work comfortably outside, a layering system should be applied to pants, socks, jackets, gloves and hats. It starts with a wicking layer to remove moisture from skin. From there it builds into heavier and more durable fabric to keep you warm.

Wicking Layer: This is the layer next to your skin. To avoid your body cooling down due to sweat, this layer should remove moisture from the skin and transfer it to the next layer. Recommended layers are synthetic or polypropylene long johns, tops and socks – no cotton!

Light Insulating Layer: This goes on after the wicking layer. A light fleece or thin wool sweater is an excellent light insulating layer.

Heavy Insulating Layer:  A heavier fleece or wool sweater begins to trap heat in the body.

Windproof-Waterproof Layer: This protects your body from a variety of weather conditions, from wind to rain or wet snow. 

Winter Toque: Thirty to 50 per cent of body heat is lost through the head. A winter hat adds as much warmth as all your layers. In winter conditions, everyone should be wearing a toque. Balaclavas can be worn under toques and are excellent for protecting facial tissue from frostbite, particularly if hard hats are mandatory in extreme cold conditions and you’re working outdoors in the open.

Mitt for working outdoors with separate index fingerGloves and Mitts: Mitts are warmer than gloves but not always practical for work that requires detail. To help with this problem, a thin glove can be worn inside a mitt. This will allow you to remove your mitts for more technical work while not exposing bare skin to the cold. Once work is completed, return your gloved hands promptly to your mitts. Also, mitts with separate index finger are very useful for certain applications.

Photo of winter boots with gaiters strapped onSocks and Gaiters: A two-layer sock system is most recommended for winter travel. A thin polypropylene sock with a wool sock over top allows moisture to be wicked from the feet and wool will stay warm even when wet. Boot size is also important – your toes need wiggle room – avoid a tight fit that restricts circulation. Some workers prefer a single pair of loose-fitting wool and/or synthetic material socks in an insulated boot, and bring a spare pair just in case.

If wearing hiking boots in the bush, gaiters are highly recommended. They prevent snow sliding down into the boots and add warmth by trapping air. Gaiters go on outside of the boot and pant leg and are great for keeping snow from entering boots

Fuel your body: Go ahead and eat up!

Working outdoors requires your body to produce heat to keep you warm. Due to the extreme conditions, it’s best to take in your calories steadily over the day. Six to eight snacks are far better than two heavy meals. Fifty per cent of your nutritional intake should be from carbohydrates such as bread and bagels. Cheese, butter, and meats add a valuable fat content to help keep your body warm.

Avoid caffeine and alcohol

Hydration is very important for winter work. On average, you should drink about four litres of water or fluids a day. If you only have a one-litre water bottle with you during the day, make sure to consume lots of hot drinks at breakfast and dinner. Drinks with caffeine (coffee or soda), or alcohol should be avoided.

Caffeine and alcohol restrict blood vessels, impeding the body’s ability to heat itself.  In the cold, water bottles will need to be insulated to prevent freezing. Cold air is dryer than warm air and we can easily lose two quarts of water an hour during strenuous activity. You may want to consider a product such as ‘Vitalyte’ as part of an emergency kit to fight of dehydration and help prevent hypothermia. 

The buddy system: Check for signs of hypothermia

“If someone in your group has begun shivering, they have mild hypothermia,” says Austin. “Hypothermia is easiest to treat at this stage, so you should immediately take steps towards a warm drink, warm food and staying active – all of which are quick sources of treatment. A hot drink or meal can do a lot to add heat to the body. As well, an extra layer and a hat or balaclava can help prevent more heat from leaving the body.

“Keeping an eye on each other is not only the key workplace safety concept behind the Internal Responsibility System,” says Austin, “it’s the best way to ensure that mild cases of hypothermia are nipped in the bud and don’t have the chance to progress to moderate or severe hypothermia.” For those with moderate hypothermia, minimizing movement is recommended along with heating blankets and warmed intravenous fluids. Severe hypothermia can include confusion, lethargy, slurred speech, and loss of consciousness. 

“Working outdoors in the wintertime can be a great experience,” says Austin, “just make sure you’re dressed properly, have adequate food and liquids, and keep an eye on your team members. Never travel and work on your own unless someone knows your route and estimated time of return. And when travelling as a group via snowmobile or ATV be sure to use the buddy system.”

Even if you are only heading out for a few hours, the proper emergency equipment is still essential. 

Related information

Is there a temperature at which work becomes dangerous and should be stopped? - Canadian Centre of Occupational Health and Safety 

White out! Winter driving tips – on and off the job - Workplace Safety North

Safety at work - Physical Exposures - Cold stress/hypothermia - WorkSafeBC

Being prepared for winter – Environment Canada

Ice Roads – Best Practices for Building and Working Safely on Ice Covers in Ontario – Ministry of Labour, Infrastructure Health and Safety Association